That introduction Haldane quote:

> You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom, it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes.

"A horse splashes". That's some mental imagery right there.

Makes me wonder if a bunch of the world's smallest flightless mammal (a fraction of the house mouse's mass) were released at altitude, would they survive? (Not proposing that this be done but thought experiments and/or simulations):

https://en.m.wikipedia.org/wiki/Etruscan_shrew

At altitude it's very cold, the shrews don't work well in the cold due to the same thing that makes them suitable for this experiment - they are very small, thus they lose heat to the environment easily. So, it's possible they freeze to death first. But yes, I imagine that if they survive the cold and aren't falling onto a hard surface (e.g. they land in grass, not a car park) they would survive.

For them other than the cold a drop from 1000 metres is the same as a drop from 10 metres.

Research is obviously warranted on the possibility of shrew blankets that can automatically detach when they touch down.

I think if we're going to give shrews blankets, we should just give the shrews blankets, not conditioned on volunteering for this potentially fatal research project.

Nah, do the same thing they did for one of the Venus landers--fasten them with something that melts. Once they have reached an altitude where the temperature won't kill them the tether melts and the blanket falls away. (On Venus they did it to cut a chute because it would have made the lander fall so slowly it would have died before landing.)

However, shrew blankets change the whole scenario to irrelevance--a shrew in a blanket sufficient to keep it safe has very different aerodynamic behavior than a naked shrew.

Isn't it proven that squirrels have a terminal velocity below what is harmful to them? [citation needed]

Shrews also starve to death if they go a few hours without food, which might complicate the logistics of the experiment a bit.

“As god is my witness I thought turkeys could fly”

https://m.youtube.com/watch?v=lf3mgmEdfwg

Turkeys can fly, though. Just not the domestic ones :)

And soon Türkiye can even fly F-16s

Türkiye has had those for decades - I remember seeing one take off from Dalaman in the early 00's while I was waiting for a flight there.

Thanks for that. I was a bit too young to appreciate WKRP when I would see it in syndication. Great line.

This gives "The Taming of the Shrew" an entirely new meaning.

Then I wonder what would happen if a Roc fell asleep midflight…

It would fade

The Roc feel air :-) (if the plane is owned by some oil company)

For science. https://www.youtube.com/watch?v=y4VmVDl8AkI

The J. B. S. Haldane essay he’s referring to is On Being the Right Size from 1926. It’s part of the anthology On Being the Right Size and Other Essays, which you can still find, and is still worth reading.

But what's the terminal velocity of a parachute backpack strapped to a mouse?

Round or rectangular parachute?

African or European mouse?

With a parachute deployed, or not?

Bellbottoms or drip coat?

Also correlation is not causation. Just because some people jumping from planes have parachutes doesn't mean that all people jumping from planes have parachutes.

Feels more like an ecological fallacy issue than a post-hoc

Wearing parachutes cause people to jump out of planes.

Surgeon General's Warning: parachutes have been known to the state of California to cause people to jump out of perfectly working planes.

Yup, *highly* skewed sample, we can't draw conclusions. The number of people who have willingly jumped from planes without desiring death is tiny. The number who have survived is even lower. (Yes, people jump without desiring death. Death by splat is better than death by fire.)

The fact that mice don't appear to deliberately jump off high things as a way to get down tells me that they probably do get hurt...

Just because they don't fall super fast doesn't mean they don't get injured because they don't have as much distance to "drop and roll" like a human does.

>The fact that mice don't appear to deliberately jump off high things as a way to get down tells me that they probably do get hurt...

Isn't this how bats have evolved though?

Not directly. There was one or more intermediary stage, probably jumping between trees. Outside my window, the squirrels are busy doing just that.

I have a vague recollection of reading that most squirrels have evidence of trauma from falling, such as healed bone fractures.

Flying squirrels show an intermediate stage of such an evolution process. Evolution always involves intermediate stages. Even if a large discrete change could occur, fine tuning it is an extended incremental process.

If you go to the Cornell Ornithology Lab feeder cam and scan through the feed at night, you will find flying squirrels at the feeder. They show signs of nocturnal adaptation, another connection to bats.

https://www.youtube.com/watch?v=N609loYkFJo

The grey squirrels in my UK garden routinely make what we call the 'leap of death' between two trees whose upper branches are a few feet apart, at different heights. I've seen two falls - one because the target branch snapped when the squirrel landed, the other during a high-speed chase where one of the squirrels apparently mis-jumped. In both cases the squirrels fell into lower level bushes and disappeared (no subsequent bodies). It's not unusual to see a squirrel with one one useless leg but still managing to feed and get around, so I can quite believe that they can recover from a broken limb given sufficient time.

* * *

We also had a pheasant who routinely visited the garden and one day showed up with a broken leg, that survived for ages before eventually disappearing. Initially he sat quietly in the undergrowth but started hopping around and doing short flights (with clumsy landings). I put out bird seed for him and he incredibly quickly learned to hoot and flap outside my back door when he was hungry. He once followed me into my shed when he was expecting feeding and had to be shoo'd out.

> The fact that mice don't appear to deliberately jump off high things as a way to get down tells me that they probably do get hurt...

They explicitly added the caveat about the soft ground. There'd be very little opportunity for mouses to become comfortable with jumping from high areas as there'd be very few occasions that satisfy the requirement. If the mouse jumped into a cave and can't get out, it'd starve to death. If it jumped off a cliff and fell into water, it would drown. If it fell off a skyscraper, there'd be Asphalt at the ground etc. Off the top of my head, there are no natural places in which mouses could safely get comfortable with jumping. Thus, they'd only do so if they're in mortal danger. And they absolutely do jump off high places if they're terrified

*mice

Mice around me fairly frequently climb trees. They know whats at the bottom of the tree (hard soil). Yet I never see them jumping off - they always climb back down the way they came up.

It could be to avoid getting disorientated though, or to be able to see a predator and reverse course...

Where I live in northern Europe almost all ground in the forests are soft. There is moss, small plants, grass or leaves everywhere.

I can't imagine why the mice would climb trees, but if they did and fall down, they probably gonna be fine most of the time.

In many forests there is lots of large rocks and steep slope/cliffs/precipice in the range 0-5 m where mice possibly could shorten their path by jumping. But I'd suppose they rather use a path they can go in both directions.

> mice don't appear to deliberately jump off high things

It could also be because they don't like to change their location too fast. You never know where you could end up. When you fall you might fall next to a cat for instance.

> The fact that mice don't appear to deliberately jump off high things as a way to get down tells me that they probably do get hurt...

It's not how this works, cats are decent swimmers yet they generally refuse to get anywhere close to water…

Well me too but if i could just jump off of stuff if be skipping the stairs a lot more often. I agree with the other person, seems logical to me that for a prey animal they'd be careful about changing their threat landscape too fast. Once you let gravity take over there's no telling where you'll land. You could roll right into a ditch or a cats paws. And maybe they actually do jump sometimes, but only when there's certainly no threat nearby, which would involve no human observers, or maybe seeing other mice where they plan to land.

And then there's the actual vision. Are mice known for being able to see long distance? One could posit, if not then most jumps would be leaps of faith into vague amorphous blobs, full of potential danger and impossible to triangulate or assess.

I tend to wear jeans with skinny legs that don't seem conducive to taking across-the-stairs (I'm thinking 3 to 5 meters in the horizontal direction) jumps.

Why do I wear impractical clothing? I never even thought of it as impractical.

Cats live warm--what is a perfect thermal balance for them (where their body needs not expend any effort for heating or cooling) is unpleasantly warm for a human (who will be sweating.) Typical water will be chilling for a cat. Going swimming in most environments will pose a hypothermia risk at times and thus fearing it is a logical evolutionary result.

They at least don't seem afraid to take the risk to walk up high vertical walls towards roofs and attics

Note that mouse survival depends on the landing. It's quite reasonable for a mouse to fear heights even if in the *typical* situation it won't be hurt. If a mouse freely jumped down and was impaled 1 time in 1,000 that would be a very bad choice for the mouse. Also, a mouse who jumps down might find itself in a situation where it can't get home.

Not in mice, but in stationary aircraft sitting on the tarmac - so even less useful than a study using mice.

It was actually done to point out the problem with studying the wrong thing.

In the first few days of their life, wood ducklings jump out of their nest and fall to the ground. If their nest is in man-made bird-box, that's probably a 4 foot drop into the water. If it's a natural nest in a tree, that might be a 50 or 60 foot drop onto the ground.

From the article:

> Parachute use did not significantly reduce death or major injury

I really recommend reading. It is a very funny thing until you realize you've read a few dozen serious articles, well received by a large community (some times even the academic community) with nearly the same kind of arguments.

The cuteness factor of mice with little parachutes might be worth it alone though!